Philip Hammond has launched a strong defence of public spending on transport infrastructure, saying it was "investing for growth".

"To those who say Britain cannot afford to invest in infrastructure, I say we cannot afford not to invest in our future," the transport secretary told the Tory conference in Manchester.

Hammond said the UK had lagged behind its competitors in infrastructure investment for 60 years, "consuming, while they were investing for the future. And the legacy of that short-termism is all around us".

Of the £30bn earmarked for transport in the last spending review, £10bn was going on roads and £20bn on public transport, he said, including "the biggest programme of rail investment since the Victorian era".

He hit out at opponents of the planned HS2 high-speed rail system that will link London, Birmingham, Manchester and Leeds, "slashing the journey time from Manchester to Euston by almost an hour, to just 73 minutes" and transforming "the social and economic geography of Britain".

He admitted the project faced "strong opposition … just as the building of the original Victorian railways did and the construction of the M25 did". But he added: "Imagine Britain now without them" and said "the job of government is to act in the interest of the nation as a whole".

In the wake of the award of the Thameslink rolling stock programme to German firm Siemens rather than the British company Bombardier earlier this year, Hammond also said that the government would be "looking at public procurement policy to make sure that UK-based firms have a fair shot at our big procurement projects".

"While I believe firmly in open markets and free trade, I also believe an open market needs a level playing field," he said.

He added that above-inflation fare increases on the railways were "not sustainable" in the medium term, and said train travel needed to be made more efficient.

The transport secretary also announced that he would soon publish "a comprehensive blueprint for reforming our railways, asking the hard questions about taxpayer subsidy and considering the options for greater local commissioning of services".

He hit out at Labour's Ed Miliband and Ed Balls, calling Miliband's conference speech last week an "ill-informed attack on the people who create the wealth and the jobs we so desperately need" and saying Balls's economic plan was to "tackle Britain's debt crisis by borrowing more, like an alcoholic in a bar with a credit card".

As expected, he announced that he was going to review the 70mph motorway speed limit – something that won applause from the audience. "I will consult on increasing the limit to 80mph," he said, adding that so many aspects of driving had changed since 1965, when the limit was introduced, that it was now out of date and widely ignored, "bringing the law into disrepute".